On Tue, Sep 02, 2025 at 09:28:32AM +0000, Teddy Astie wrote: > From: Juergen Gross <[email protected]> > > From: Juergen Gross <[email protected]> > > [ upstream commit 41925b105e345ebc84cedb64f59d20cb14a62613 ] > > xen_remap() is used to establish mappings for frames not under direct > control of the kernel: for Xenstore and console ring pages, and for > grant pages of non-PV guests. > > Today xen_remap() is defined to use ioremap() on x86 (doing uncached > mappings), and ioremap_cache() on Arm (doing cached mappings). > > Uncached mappings for those use cases are bad for performance, so they > should be avoided if possible. As all use cases of xen_remap() don't > require uncached mappings (the mapped area is always physical RAM), > a mapping using the standard WB cache mode is fine. > > As sparse is flagging some of the xen_remap() use cases to be not > appropriate for iomem(), as the result is not annotated with the > __iomem modifier, eliminate xen_remap() completely and replace all > use cases with memremap() specifying the MEMREMAP_WB caching mode. > > xen_unmap() can be replaced with memunmap(). > > Reported-by: kernel test robot <[email protected]> > Signed-off-by: Juergen Gross <[email protected]> > Reviewed-by: Boris Ostrovsky <[email protected]> > Acked-by: Stefano Stabellini <[email protected]> > Link: https://lore.kernel.org/r/[email protected] > Signed-off-by: Juergen Gross <[email protected]> > Signed-off-by: Teddy Astie <[email protected]> [backport to 5.10.y] > ---
Why is this needed for 5.10.y at all? What bug does it fix? And why are you still using Xen on a 5.10.y kernel? What prevents you from moving to a newer one? thanks, greg k-h
